Abstract：Tunable diode-laser absorption spectroscopy techniques have been widely used in many regions，such as environmental monitoring and detection of industrial process，due to their high spectral resolution，high sensitivity，fast time response and non-intrusive character. It’s important to obtain absorbance curve and integrated absorbance for gas concentration inversion and line strength calibration in direct-absorption spectroscopy techniques. An approach was taken to process the laser direct absorption spectrum. First a low-order polynomial baseline fitting was carried on sub-regions of the transmitted signal to eliminate the effect of diode-laser output fluctuation and obtain the absorbance curve. Then integrated absorbance can be inverted through line-shape fitting using Levenberg-Marquardt non-linear least-squares fitting method. This approach was verified by experimental processing of absorption lines of water vapor.
Key words：Absorbance;Baseline fitting;None-linear least squares method
许振宇，刘文清*，阚瑞峰，张玉钧，刘建国，张 帅，束小文，耿 辉，何 莹，汤媛媛 . 可调谐半导体激光吸收光谱中的吸光度反演算法研究 [J]. 光谱学与光谱分析, 2010, 30(08): 2201-2204.
XU Zhen-yu, LIU Wen-qing*, KAN Rui-feng, ZHANG Yu-jun, LIU Jian-guo, ZHANG Shuai, SHU Xiao-wen, GENG Hui, HE Ying, TANG Yuan-yuan . Study on the Arithmetic of Absorbance Inversion Based on Tunable Diode-Laser Absorption Spectroscopy . SPECTROSCOPY AND SPECTRAL ANALYSIS, 2010, 30(08): 2201-2204.
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